My black & decker gr3800 rotary mower is slow to start when the motor gets warm and sometimes the motor rums in reverse

SOURCE: Can't start my mm525 black and decker electric mower

checked out dewaltservicenet for further info.
maybe a broken switch our possible broken armature comm

SOURCE: Mower tripped outlet breaker - wiring schematic available?

I had a MM875 go out after some months' service -- it actually went out with a bit of a bang. The problem was a shorted circuit; the weather was hot and the "solid state switch" on top of the motor shorted out. This part wasn't a switch but a bridge rectifier. The original part was specified a bit close to its actual working limits so I bought another (from Radio Shack, no less) that was higher rating -- something like 30 amps at 200 or 400 volts. ITs worked for years.

If it is a bridge then it will have two terminals labelled '~' and one each with the '+' and '-'. The plus and minus go to the motor (keep those connections the same as the original) and the others go to the supply wires.

Jim Goldsmith

• 2005 Answers
• Posted on May 21, 2009

SOURCE: electric lawn mower slowed down then stopped working?

The carbon brushes on your mower have worn and, need to be replaced; order them from black & decker

SOURCE: wiring diagram for a cordless Black & Decker CMM1000 Ver 2 Mower

All set, figured it out.

SOURCE: WIRING DIAGRAM? FOR BLACK AND DECKER ELECTRIC LAWN MOWER MM 850

looking down at the terminals, rotate push-button to the right. the wiring sequence is R, W at the top, then Black (in, from power source) , Black (out, to motor).